Dry Abrasion Resistance of an Antimicrobial Quaternary Ammonium Coating Bonded to Stainless-Steel Surfaces and Challenged by Listeria innocua and Escherichia Coli K12

This research investigated the resilience of a quaternary ammonium (QAC) coating to repeated dry abrasions while still maintaining its antimicrobial efficacy to Listeria innocua and Escherichia coli K12. Physico-chemical changes to the coating during dry abrasion applications were also investigated. The antimicrobial effectiveness of the QAC was tested by inoculating coated surfaces with bacteria before and after dry abrasions. Physico-chemical changes to the coating were determined by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) analyses. Results showed that the coating inactivated L. innocua and E. coli K12 after 60 and 120 rub cycles, respectively. A second application of the coating, after the first coating was removed by abrasion, gave the stainless-steel a similar inactivation ability against L. innocua when compared with the first coating. The SEM/EDS analyses showed a decline in carbon, oxygen, silicon, and chlorine elements plus degradation of the coated surfaces after 120 rub cycles. This study demonstrated the potential of this QAC coating for use on high-touch surfaces to reduce microbial cross-contamination and to provide a reference for improvements to coating formulations against dry abrasions.